
/* -----------------------------------------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android

© Copyright  1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
  All rights reserved.

 1.    INTRODUCTION
The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
This FDK AAC Codec software is intended to be used on a wide variety of Android devices.

AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
of the MPEG specifications.

Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
individually for the purpose of encoding or decoding bit streams in products that are compliant with
the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
software may already be covered under those patent licenses when it is used for those licensed purposes only.

Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
applications information and documentation.

2.    COPYRIGHT LICENSE

Redistribution and use in source and binary forms, with or without modification, are permitted without
payment of copyright license fees provided that you satisfy the following conditions:

You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
your modifications thereto in source code form.

You must retain the complete text of this software license in the documentation and/or other materials
provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
modifications thereto to recipients of copies in binary form.

The name of Fraunhofer may not be used to endorse or promote products derived from this library without
prior written permission.

You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
software or your modifications thereto.

Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
and the date of any change. For modified versions of the FDK AAC Codec, the term
"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."

3.    NO PATENT LICENSE

NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
respect to this software.

You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
by appropriate patent licenses.

4.    DISCLAIMER

This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
or business interruption, however caused and on any theory of liability, whether in contract, strict
liability, or tort (including negligence), arising in any way out of the use of this software, even if
advised of the possibility of such damage.

5.    CONTACT INFORMATION

Fraunhofer Institute for Integrated Circuits IIS
Attention: Audio and Multimedia Departments - FDK AAC LL
Am Wolfsmantel 33
91058 Erlangen, Germany

www.iis.fraunhofer.de/amm
amm-info@iis.fraunhofer.de
----------------------------------------------------------------------------------------------------------- */

 /******************************** MPEG Audio Encoder **************************

   Initial author:       M. Werner
   contents/description: Bitstream encoder

******************************************************************************/

#include "bitenc.h"
#include "bit_cnt.h"
#include "dyn_bits.h"
#include "qc_data.h"
#include "interface.h"
#include "aacEnc_ram.h"


#include "tpenc_lib.h"

#include "FDK_tools_rom.h"  /* needed for the bitstream syntax tables */

static const int globalGainOffset = 100;
static const int icsReservedBit   = 0;
static const int noiseOffset      = 90;

/*****************************************************************************

    functionname: FDKaacEnc_encodeSpectralData
    description:  encode spectral data
    returns:      the number of written bits
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeSpectralData(INT                    *sfbOffset,
                                        SECTION_DATA           *sectionData,
                                        SHORT                  *quantSpectrum,
                                        HANDLE_FDK_BITSTREAM    hBitStream)
{
  INT i,sfb;
  INT dbgVal = FDKgetValidBits(hBitStream);

  for(i=0;i<sectionData->noOfSections;i++)
  {
    if(sectionData->huffsection[i].codeBook != CODE_BOOK_PNS_NO)
    {
      /* huffencode spectral data for this huffsection */
      INT tmp = sectionData->huffsection[i].sfbStart+sectionData->huffsection[i].sfbCnt;
      for(sfb=sectionData->huffsection[i].sfbStart; sfb<tmp; sfb++)
      {
        FDKaacEnc_codeValues(quantSpectrum+sfbOffset[sfb],
                             sfbOffset[sfb+1]-sfbOffset[sfb],
                             sectionData->huffsection[i].codeBook,
                             hBitStream);
      }
    }
  }
  return(FDKgetValidBits(hBitStream)-dbgVal);
}

/*****************************************************************************

    functionname:FDKaacEnc_encodeGlobalGain
    description: encodes Global Gain (common scale factor)
    returns:     the number of static bits
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeGlobalGain(INT globalGain,
                                      INT scalefac,
                                      HANDLE_FDK_BITSTREAM hBitStream,
                                      INT mdctScale)
{
  if (hBitStream != NULL) {
    FDKwriteBits(hBitStream,globalGain - scalefac + globalGainOffset-4*(LOG_NORM_PCM-mdctScale),8);
  }
  return (8);
}


/*****************************************************************************

    functionname:FDKaacEnc_encodeIcsInfo
    description: encodes Ics Info
    returns:     the number of static bits
    input:
    output:

*****************************************************************************/

static INT FDKaacEnc_encodeIcsInfo(INT blockType,
                                   INT windowShape,
                                   INT groupingMask,
                                   INT maxSfbPerGroup,
                                   HANDLE_FDK_BITSTREAM  hBitStream,
                                   UINT syntaxFlags)
{
  INT statBits;

  if (blockType == SHORT_WINDOW) {
    statBits = 8 + TRANS_FAC - 1;
  } else {
    if (syntaxFlags & AC_ELD) {
      statBits = 6;
    } else
    {
      statBits = (!(syntaxFlags & AC_SCALABLE)) ? 11 : 10;
    }
  }

  if (hBitStream != NULL) {

    if (!(syntaxFlags & AC_ELD)){
      FDKwriteBits(hBitStream,icsReservedBit,1);
      FDKwriteBits(hBitStream,blockType,2);
      FDKwriteBits(hBitStream, (windowShape == LOL_WINDOW) ? KBD_WINDOW : windowShape,1);
    }

    switch(blockType){
    case LONG_WINDOW:
    case START_WINDOW:
    case STOP_WINDOW:
      FDKwriteBits(hBitStream,maxSfbPerGroup,6);

      if (!(syntaxFlags & (AC_SCALABLE|AC_ELD)) ) { /* If not scalable syntax then ... */
        /* No predictor data present */
        FDKwriteBits(hBitStream, 0, 1);
      }
      break;

    case SHORT_WINDOW:
      FDKwriteBits(hBitStream,maxSfbPerGroup,4);

      /* Write grouping bits */
      FDKwriteBits(hBitStream,groupingMask,TRANS_FAC-1);
      break;
    }
  }

  return (statBits);
}

/*****************************************************************************

    functionname: FDKaacEnc_encodeSectionData
    description:  encode section data (common Huffman codebooks for adjacent
                  SFB's)
    returns:      none
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeSectionData(SECTION_DATA *sectionData,
                                       HANDLE_FDK_BITSTREAM hBitStream,
                                       UINT useVCB11)
{
  if (hBitStream != NULL) {
    INT sectEscapeVal=0,sectLenBits=0;
    INT sectLen;
    INT i;
    INT dbgVal=FDKgetValidBits(hBitStream);
    INT sectCbBits = 4;

    switch(sectionData->blockType)
    {
    case LONG_WINDOW:
    case START_WINDOW:
    case STOP_WINDOW:
      sectEscapeVal = SECT_ESC_VAL_LONG;
      sectLenBits   = SECT_BITS_LONG;
      break;

    case SHORT_WINDOW:
      sectEscapeVal = SECT_ESC_VAL_SHORT;
      sectLenBits   = SECT_BITS_SHORT;
      break;
    }

    for(i=0;i<sectionData->noOfSections;i++)
    {
      INT codeBook = sectionData->huffsection[i].codeBook;

      FDKwriteBits(hBitStream,codeBook,sectCbBits);

      {
        sectLen = sectionData->huffsection[i].sfbCnt;

        while(sectLen >= sectEscapeVal)
        {
          FDKwriteBits(hBitStream,sectEscapeVal,sectLenBits);
          sectLen-=sectEscapeVal;
        }
        FDKwriteBits(hBitStream,sectLen,sectLenBits);
      }
    }
    return(FDKgetValidBits(hBitStream)-dbgVal);
  }
  return (0);
}

/*****************************************************************************

    functionname: FDKaacEnc_encodeScaleFactorData
    description:  encode DPCM coded scale factors
    returns:      none
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeScaleFactorData(UINT                  *maxValueInSfb,
                                           SECTION_DATA          *sectionData,
                                           INT                   *scalefac,
                                           HANDLE_FDK_BITSTREAM   hBitStream,
                                           const INT             *isScale,
                                           INT                    globalGain)
{
  if (hBitStream != NULL) {
    INT i,j,lastValScf,deltaScf;
    INT noisePCMFlag = TRUE;
    INT lastValIs;

    INT dbgVal = FDKgetValidBits(hBitStream);

    lastValScf=scalefac[sectionData->firstScf];
    lastValIs  = 0;

    for(i=0; i<sectionData->noOfSections; i++){
      if (sectionData->huffsection[i].codeBook != CODE_BOOK_ZERO_NO) {

        if ((sectionData->huffsection[i].codeBook == CODE_BOOK_IS_OUT_OF_PHASE_NO) ||
            (sectionData->huffsection[i].codeBook == CODE_BOOK_IS_IN_PHASE_NO))
        {
          INT sfbStart = sectionData->huffsection[i].sfbStart;
          INT tmp = sfbStart + sectionData->huffsection[i].sfbCnt;
          for(j=sfbStart; j<tmp; j++) {
            INT deltaIs   = isScale[j]-lastValIs;
            lastValIs = isScale[j];
            if(FDKaacEnc_codeScalefactorDelta(deltaIs,hBitStream)) {
                return(1);
            }
          } /* sfb */
        }
        else {
          INT tmp = sectionData->huffsection[i].sfbStart+sectionData->huffsection[i].sfbCnt;
          for(j=sectionData->huffsection[i].sfbStart; j<tmp; j++){
            /*
              check if we can repeat the last value to save bits
            */
            if(maxValueInSfb[j] == 0)
              deltaScf = 0;
            else{
              deltaScf = -(scalefac[j]-lastValScf);
              lastValScf = scalefac[j];
            }
            if(FDKaacEnc_codeScalefactorDelta(deltaScf,hBitStream)){
              return(1);
            }
          } /* sfb */
        } /* code scalefactor */
      } /* sectionData->huffsection[i].codeBook != CODE_BOOK_ZERO_NO */
    } /* section loop */

    return(FDKgetValidBits(hBitStream)-dbgVal);
  } /* if (hBitStream != NULL) */

  return (0);
}

/*****************************************************************************

    functionname:encodeMsInfo
    description: encodes MS-Stereo Info
    returns:     the number of static bits
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeMSInfo(INT            sfbCnt,
                                  INT            grpSfb,
                                  INT            maxSfb,
                                  INT            msDigest,
                                  INT           *jsFlags,
                                  HANDLE_FDK_BITSTREAM hBitStream)
{
  INT sfb, sfbOff, msBits = 0;

  if (hBitStream != NULL)
  {
    switch(msDigest)
    {
    case MS_NONE:
      FDKwriteBits(hBitStream,SI_MS_MASK_NONE,2);
      msBits += 2;
      break;

    case MS_ALL:
      FDKwriteBits(hBitStream,SI_MS_MASK_ALL,2);
      msBits += 2;
      break;

    case MS_SOME:
      FDKwriteBits(hBitStream,SI_MS_MASK_SOME,2);
      msBits += 2;
      for(sfbOff = 0; sfbOff < sfbCnt; sfbOff+=grpSfb)
      {
        for(sfb=0; sfb<maxSfb; sfb++)
        {
          if(jsFlags[sfbOff+sfb] & MS_ON){
            FDKwriteBits(hBitStream,1,1);
          }
          else{
            FDKwriteBits(hBitStream,0,1);
          }
          msBits += 1;
        }
      }
      break;
    }
  }
  else {
    msBits += 2;
    if (msDigest == MS_SOME) {
      for(sfbOff = 0; sfbOff < sfbCnt; sfbOff+=grpSfb) {
        for(sfb=0; sfb<maxSfb; sfb++) {
          msBits += 1;
        }
      }
    }
  }
  return (msBits);
}

/*****************************************************************************

    functionname: FDKaacEnc_encodeTnsDataPresent
    description:  encode TNS data (filter order, coeffs, ..)
    returns:      the number of static bits
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeTnsDataPresent(HANDLE_FDK_BITSTREAM hBitStream)
{
  if ( (hBitStream!=NULL) )
  {
    FDKwriteBits(hBitStream,0,1);
  }
  return (1);
}

/*****************************************************************************

    functionname: FDKaacEnc_encodeTnsData
    description:  encode TNS data (filter order, coeffs, ..)
    returns:      the number of static bits
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeTnsData(HANDLE_FDK_BITSTREAM hBitStream)
{
  return (0);
}

/*****************************************************************************

    functionname: FDKaacEnc_encodeGainControlData
    description:  unsupported
    returns:      none
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodeGainControlData(HANDLE_FDK_BITSTREAM hBitStream)
{
  if (hBitStream != NULL) {
    FDKwriteBits(hBitStream,0,1);
  }
  return (1);
}

/*****************************************************************************

    functionname: FDKaacEnc_encodePulseData
    description:  not supported yet (dummy)
    returns:      none
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_encodePulseData(HANDLE_FDK_BITSTREAM hBitStream)
{
  if (hBitStream != NULL) {
    FDKwriteBits(hBitStream,0,1);
  }
  return (1);
}


/*****************************************************************************

    functionname: FDKaacEnc_writeExtensionPayload
    description:  write extension payload to bitstream
    returns:      number of written bits
    input:
    output:

*****************************************************************************/
static INT FDKaacEnc_writeExtensionPayload( HANDLE_FDK_BITSTREAM  hBitStream,
                                            EXT_PAYLOAD_TYPE      extPayloadType,
                                            const UCHAR          *extPayloadData,
                                            INT                   extPayloadBits
                                          )
{
  #define EXT_TYPE_BITS         ( 4 )
  #define DATA_EL_VERSION_BITS  ( 4 )
  #define FILL_NIBBLE_BITS      ( 4 )

  INT  extBitsUsed = 0;

  if (extPayloadBits >= EXT_TYPE_BITS)
  {
    UCHAR  fillByte = 0x00;  /* for EXT_FIL and EXT_FILL_DATA */

    if (hBitStream != NULL) {
      FDKwriteBits(hBitStream, extPayloadType, EXT_TYPE_BITS);
    }
    extBitsUsed += EXT_TYPE_BITS;

    switch (extPayloadType) {
      case EXT_DYNAMIC_RANGE:
      /* case EXT_SAC_DATA: */
      case EXT_SBR_DATA:
      case EXT_SBR_DATA_CRC:
        if (hBitStream != NULL) {
          int i, writeBits = extPayloadBits;
          for (i=0; writeBits >= 8; i++) {
            FDKwriteBits(hBitStream, extPayloadData[i], 8);
            writeBits -= 8;
          }
          if (writeBits > 0) {
            FDKwriteBits(hBitStream, extPayloadData[i]>>(8-writeBits), writeBits);
          }
        }
        extBitsUsed += extPayloadBits;
        break;

      case EXT_DATA_ELEMENT:
        {
          INT dataElementLength = (extPayloadBits+7)>>3;
          INT cnt = dataElementLength;
          int loopCounter = 1;

          while (dataElementLength >= 255) {
            loopCounter++;
            dataElementLength -= 255;
          }

          if (hBitStream != NULL) {
            int i;
            FDKwriteBits(hBitStream, 0x00, DATA_EL_VERSION_BITS);  /* data_element_version = ANC_DATA */

            for (i=1; i<loopCounter; i++) {
              FDKwriteBits(hBitStream, 255, 8);
            }
            FDKwriteBits(hBitStream, dataElementLength, 8);

            for (i=0; i<cnt; i++) {
              FDKwriteBits(hBitStream, extPayloadData[i], 8);
            }
          }
          extBitsUsed += DATA_EL_VERSION_BITS + (loopCounter*8) + (cnt*8);
        }
        break;

      case EXT_FILL_DATA:
        fillByte = 0xA5;
      case EXT_FIL:
      default:
        if (hBitStream != NULL) {
          int writeBits = extPayloadBits;
          FDKwriteBits(hBitStream, 0x00, FILL_NIBBLE_BITS);
          writeBits -= 8;  /* acount for the extension type and the fill nibble */
          while (writeBits >= 8) {
            FDKwriteBits(hBitStream, fillByte, 8);
            writeBits -= 8;
          }
        }
        extBitsUsed += FILL_NIBBLE_BITS + (extPayloadBits & ~0x7) - 8;
        break;
    }
  }

  return (extBitsUsed);
}


/*****************************************************************************

    functionname: FDKaacEnc_writeDataStreamElement
    description:  write data stream elements like ancillary data ...
    returns:      the amount of used bits
    input:
    output:

******************************************************************************/
static INT FDKaacEnc_writeDataStreamElement( HANDLE_TRANSPORTENC  hTpEnc,
                                             INT    elementInstanceTag,
                                             INT    dataPayloadBytes,
                                             UCHAR *dataBuffer,
                                             UINT   alignAnchor )
{
  #define DATA_BYTE_ALIGN_FLAG      ( 0 )

  #define EL_INSTANCE_TAG_BITS      ( 4 )
  #define DATA_BYTE_ALIGN_FLAG_BITS ( 1 )
  #define DATA_LEN_COUNT_BITS       ( 8 )
  #define DATA_LEN_ESC_COUNT_BITS   ( 8 )

  #define MAX_DATA_ALIGN_BITS       ( 7 )
  #define MAX_DSE_DATA_BYTES        ( 510 )

  INT  dseBitsUsed = 0;

  while (dataPayloadBytes > 0)
  {
    int esc_count = -1;
    int cnt = 0;
    INT crcReg = -1;

    dseBitsUsed += EL_ID_BITS + EL_INSTANCE_TAG_BITS
                +  DATA_BYTE_ALIGN_FLAG_BITS + DATA_LEN_COUNT_BITS;

    if (DATA_BYTE_ALIGN_FLAG) {
      dseBitsUsed += MAX_DATA_ALIGN_BITS;
    }

    cnt = fixMin(MAX_DSE_DATA_BYTES, dataPayloadBytes);
    if ( cnt >= 255 ) {
      esc_count = cnt - 255;
      dseBitsUsed += DATA_LEN_ESC_COUNT_BITS;
    }

    dataPayloadBytes -= cnt;
    dseBitsUsed += cnt * 8;

    if (hTpEnc != NULL) {
      HANDLE_FDK_BITSTREAM hBitStream = transportEnc_GetBitstream(hTpEnc);
      int i;

      FDKwriteBits(hBitStream, ID_DSE, EL_ID_BITS);

      crcReg = transportEnc_CrcStartReg(hTpEnc, 0);

      FDKwriteBits(hBitStream, elementInstanceTag, EL_INSTANCE_TAG_BITS);
      FDKwriteBits(hBitStream, DATA_BYTE_ALIGN_FLAG, DATA_BYTE_ALIGN_FLAG_BITS);

      /* write length field(s) */
      if ( esc_count >= 0 ) {
        FDKwriteBits(hBitStream, 255, DATA_LEN_COUNT_BITS);
        FDKwriteBits(hBitStream, esc_count, DATA_LEN_ESC_COUNT_BITS);
      } else {
        FDKwriteBits(hBitStream, cnt, DATA_LEN_COUNT_BITS);
      }

      if (DATA_BYTE_ALIGN_FLAG) {
        INT tmp = (INT)FDKgetValidBits(hBitStream);
        FDKbyteAlign(hBitStream, alignAnchor);
        /* count actual bits */
        dseBitsUsed += (INT)FDKgetValidBits(hBitStream) - tmp - MAX_DATA_ALIGN_BITS;
      }

      /* write payload */
      for (i=0; i<cnt; i++) {
        FDKwriteBits(hBitStream, dataBuffer[i], 8);
      }
      transportEnc_CrcEndReg(hTpEnc, crcReg);
    }
  }

  return (dseBitsUsed);
}


/*****************************************************************************

    functionname: FDKaacEnc_writeExtensionData
    description:  write extension payload to bitstream
    returns:      number of written bits
    input:
    output:

*****************************************************************************/
INT FDKaacEnc_writeExtensionData( HANDLE_TRANSPORTENC  hTpEnc,
                                  QC_OUT_EXTENSION    *pExtension,
                                  INT                  elInstanceTag, /* for DSE only */
                                  UINT                 alignAnchor,   /* for DSE only */
                                  UINT                 syntaxFlags,
                                  AUDIO_OBJECT_TYPE    aot,
                                  SCHAR                epConfig
                                )
{
  #define FILL_EL_COUNT_BITS      ( 4 )
  #define FILL_EL_ESC_COUNT_BITS  ( 8 )
  #define MAX_FILL_DATA_BYTES     ( 269 )

  HANDLE_FDK_BITSTREAM hBitStream = NULL;
  INT payloadBits = pExtension->nPayloadBits;
  INT extBitsUsed = 0;

  if (hTpEnc != NULL) {
    hBitStream = transportEnc_GetBitstream(hTpEnc);
  }

  if (syntaxFlags & (AC_SCALABLE|AC_ER))
  {
    if ( syntaxFlags & AC_DRM )
    { /* CAUTION: The caller has to assure that fill
                  data is written before the SBR payload. */
      UCHAR *extPayloadData = pExtension->pPayload;

      switch (pExtension->type)
      {
        case EXT_SBR_DATA:
        case EXT_SBR_DATA_CRC:
          /* SBR payload is written in reverse */
          if (hBitStream != NULL) {
            int   i, writeBits = payloadBits;

            FDKpushFor(hBitStream, payloadBits-1);  /* Does a cache sync internally */

            for (i=0; writeBits >= 8; i++) {
              FDKwriteBitsBwd(hBitStream, extPayloadData[i], 8);
              writeBits -= 8;
            }
            if (writeBits > 0) {
              FDKwriteBitsBwd(hBitStream, extPayloadData[i]>>(8-writeBits), writeBits);
            }

            FDKsyncCacheBwd (hBitStream);
            FDKpushFor (hBitStream, payloadBits+1);
          }
          extBitsUsed += payloadBits;
          break;

        case EXT_FILL_DATA:
        case EXT_FIL:
        default:
          if (hBitStream != NULL) {
            int writeBits = payloadBits;
            while (writeBits >= 8) {
              FDKwriteBits(hBitStream, 0x00, 8);
              writeBits -= 8;
            }
            FDKwriteBits(hBitStream, 0x00, writeBits);
          }
          extBitsUsed += payloadBits;
          break;
      }
    }
    else {
      if ( (syntaxFlags & AC_ELD) && ((pExtension->type==EXT_SBR_DATA) || (pExtension->type==EXT_SBR_DATA_CRC)) ) {

        if (hBitStream != NULL) {
          int i, writeBits = payloadBits;
          UCHAR *extPayloadData = pExtension->pPayload;

          for (i=0; writeBits >= 8; i++) {
            FDKwriteBits(hBitStream, extPayloadData[i], 8);
            writeBits -= 8;
          }
          if (writeBits > 0) {
            FDKwriteBits(hBitStream, extPayloadData[i]>>(8-writeBits), writeBits);
          }
        }
        extBitsUsed += payloadBits;
      }
      else
      {
        /* ER or scalable syntax -> write extension en bloc */
        extBitsUsed += FDKaacEnc_writeExtensionPayload( hBitStream,
                                                        pExtension->type,
                                                        pExtension->pPayload,
                                                        payloadBits );
      }
    }
  }
  else {
    /* We have normal GA bitstream payload (AOT 2,5,29) so pack
       the data into a fill elements or DSEs */

    if ( pExtension->type == EXT_DATA_ELEMENT )
    {
      extBitsUsed += FDKaacEnc_writeDataStreamElement( hTpEnc,
                                                       elInstanceTag,
                                                       pExtension->nPayloadBits>>3,
                                                       pExtension->pPayload,
                                                       alignAnchor );
    }
    else {
      while (payloadBits >= (EL_ID_BITS + FILL_EL_COUNT_BITS)) {
        INT cnt, esc_count=-1, alignBits=7;

        if ( (pExtension->type == EXT_FILL_DATA) || (pExtension->type == EXT_FIL) )
        {
          payloadBits -= EL_ID_BITS + FILL_EL_COUNT_BITS;
          if (payloadBits >= 15*8) {
            payloadBits -= FILL_EL_ESC_COUNT_BITS;
            esc_count = 0;  /* write esc_count even if cnt becomes smaller 15 */
          }
          alignBits = 0;
        }

        cnt = fixMin(MAX_FILL_DATA_BYTES, (payloadBits+alignBits)>>3);

        if (cnt >= 15) {
          esc_count = cnt - 15 + 1;
        }

        if (hBitStream != NULL) {
          /* write bitstream */
          FDKwriteBits(hBitStream, ID_FIL, EL_ID_BITS);
          if (esc_count >= 0) {
            FDKwriteBits(hBitStream, 15, FILL_EL_COUNT_BITS);
            FDKwriteBits(hBitStream, esc_count, FILL_EL_ESC_COUNT_BITS);
          } else {
            FDKwriteBits(hBitStream, cnt, FILL_EL_COUNT_BITS);
          }
        }

        extBitsUsed += EL_ID_BITS + FILL_EL_COUNT_BITS + ((esc_count>=0) ? FILL_EL_ESC_COUNT_BITS : 0);

        cnt = fixMin(cnt*8, payloadBits);  /* convert back to bits */
        extBitsUsed += FDKaacEnc_writeExtensionPayload( hBitStream,
                                                        pExtension->type,
                                                        pExtension->pPayload,
                                                        cnt );
        payloadBits -= cnt;
      }
    }
  }

  return (extBitsUsed);
}


/*****************************************************************************

    functionname: FDKaacEnc_ByteAlignment
    description:
    returns:
    input:
    output:

*****************************************************************************/
static void FDKaacEnc_ByteAlignment(HANDLE_FDK_BITSTREAM hBitStream, int alignBits)
{
  FDKwriteBits(hBitStream, 0, alignBits);
}

AAC_ENCODER_ERROR FDKaacEnc_ChannelElementWrite( HANDLE_TRANSPORTENC  hTpEnc,
                                                 ELEMENT_INFO        *pElInfo,
                                                 QC_OUT_CHANNEL      *qcOutChannel[(2)],
                                                 PSY_OUT_ELEMENT     *psyOutElement,
                                                 PSY_OUT_CHANNEL     *psyOutChannel[(2)],
                                                 UINT                 syntaxFlags,
                                                 AUDIO_OBJECT_TYPE    aot,
                                                 SCHAR                epConfig,
                                                 INT                 *pBitDemand,
                                                 UCHAR                minCnt
                                               )
{
  AAC_ENCODER_ERROR error = AAC_ENC_OK;
  HANDLE_FDK_BITSTREAM hBitStream = NULL;
  INT    bitDemand = 0;
  const  element_list_t *list;
  int    i, ch, decision_bit;
  INT    crcReg1 = -1, crcReg2 = -1;
  UCHAR  numberOfChannels;

  if (hTpEnc != NULL) {
    /* Get bitstream handle */
    hBitStream = transportEnc_GetBitstream(hTpEnc);
  }

  if ( (pElInfo->elType==ID_SCE) || (pElInfo->elType==ID_LFE) ) {
    numberOfChannels = 1;
  } else {
    numberOfChannels = 2;
  }

  /* Get channel element sequence table */
  list = getBitstreamElementList(aot, epConfig, numberOfChannels, 0);
  if (list == NULL) {
    error = AAC_ENC_UNSUPPORTED_AOT;
    goto bail;
  }

  if (!(syntaxFlags & (AC_SCALABLE|AC_ER))) {
    if (hBitStream != NULL) {
      FDKwriteBits(hBitStream, pElInfo->elType, EL_ID_BITS);
    }
    bitDemand += EL_ID_BITS;
  }

  /* Iterate through sequence table */
  i = 0;
  ch = 0;
  decision_bit = 0;
  do {
    /* some tmp values */
    SECTION_DATA *pChSectionData = NULL;
    INT  *pChScf           = NULL;
    UINT *pChMaxValueInSfb = NULL;
    INT   chGlobalGain     = 0;
    INT   chBlockType      = 0;
    INT   chMaxSfbPerGrp   = 0;
    INT   chSfbPerGrp      = 0;
    INT   chSfbCnt         = 0;
    INT   chFirstScf       = 0;

    if (minCnt==0) {
      if ( qcOutChannel!=NULL ) {
        pChSectionData   = &(qcOutChannel[ch]->sectionData);
        pChScf           =  qcOutChannel[ch]->scf;
        chGlobalGain     =  qcOutChannel[ch]->globalGain;
        pChMaxValueInSfb =  qcOutChannel[ch]->maxValueInSfb;
        chBlockType      =  pChSectionData->blockType;
        chMaxSfbPerGrp   =  pChSectionData->maxSfbPerGroup;
        chSfbPerGrp      =  pChSectionData->sfbPerGroup;
        chSfbCnt         =  pChSectionData->sfbCnt;
        chFirstScf       =  pChScf[pChSectionData->firstScf];
      }
      else {
        /* get values from PSY */
        chSfbCnt       = psyOutChannel[ch]->sfbCnt;
        chSfbPerGrp    = psyOutChannel[ch]->sfbPerGroup;
        chMaxSfbPerGrp = psyOutChannel[ch]->maxSfbPerGroup;
      }
    } /* minCnt==0 */

    if ( qcOutChannel==NULL ) {
      chBlockType    = psyOutChannel[ch]->lastWindowSequence;
    }

    switch (list->id[i])
    {
    case element_instance_tag:
      /* Write element instance tag */
      if (hBitStream != NULL) {
        FDKwriteBits(hBitStream, pElInfo->instanceTag, 4);
      }
      bitDemand += 4;
      break;

    case common_window:
      /* Write common window flag */
      decision_bit = psyOutElement->commonWindow;
      if (hBitStream != NULL) {
        FDKwriteBits(hBitStream, psyOutElement->commonWindow, 1);
      }
      bitDemand += 1;
      break;

    case ics_info:
      /* Write individual channel info */
      bitDemand += FDKaacEnc_encodeIcsInfo( chBlockType,
                                            psyOutChannel[ch]->windowShape,
                                            psyOutChannel[ch]->groupingMask,
                                            chMaxSfbPerGrp,
                                            hBitStream,
                                            syntaxFlags);
      break;

    case ltp_data_present:
      /* Write LTP data present flag */
      if (hBitStream != NULL) {
        FDKwriteBits(hBitStream, 0, 1);
      }
      bitDemand += 1;
      break;

    case ltp_data:
      /* Predictor data not supported.
         Nothing to do here. */
      break;

    case ms:
      /* Write MS info */
      bitDemand += FDKaacEnc_encodeMSInfo( chSfbCnt,
                                           chSfbPerGrp,
                                           chMaxSfbPerGrp,
                                           (minCnt==0) ? psyOutElement->toolsInfo.msDigest : MS_NONE,
                                           psyOutElement->toolsInfo.msMask,
                                           hBitStream);
      break;

    case global_gain:
      bitDemand += FDKaacEnc_encodeGlobalGain( chGlobalGain,
                                               chFirstScf,
                                               hBitStream,
                                               psyOutChannel[ch]->mdctScale );
      break;

    case section_data:
      {
        INT siBits = FDKaacEnc_encodeSectionData(pChSectionData, hBitStream, (syntaxFlags & AC_ER_VCB11)?1:0);
        if (hBitStream != NULL) {
          if (siBits != qcOutChannel[ch]->sectionData.sideInfoBits) {
            error = AAC_ENC_WRITE_SEC_ERROR;
          }
        }
        bitDemand += siBits;
      }
      break;

    case scale_factor_data:
      {
        INT sfDataBits = FDKaacEnc_encodeScaleFactorData( pChMaxValueInSfb,
                                                          pChSectionData,
                                                          pChScf,
                                                          hBitStream,
                                                          psyOutChannel[ch]->isScale,
                                                          chGlobalGain );
        if ( (hBitStream != NULL)
          && (sfDataBits != (qcOutChannel[ch]->sectionData.scalefacBits)) ) {
           error = AAC_ENC_WRITE_SCAL_ERROR;
        }
        bitDemand += sfDataBits;
      }
      break;

    case esc2_rvlc:
      if (syntaxFlags & AC_ER_RVLC) {
        /* write RVLC data into bitstream (error sens. cat. 2) */
        error = AAC_ENC_UNSUPPORTED_AOT;
      }
      break;

    case pulse:
      /* Write pulse data */
      bitDemand += FDKaacEnc_encodePulseData(hBitStream);
      break;

    case tns_data_present:
      /* Write TNS data present flag */
      bitDemand += FDKaacEnc_encodeTnsDataPresent(hBitStream);
      break;
    case tns_data:
      /* Write TNS data */
      bitDemand += FDKaacEnc_encodeTnsData(hBitStream);
      break;

    case gain_control_data:
      /* Nothing to do here */
      break;

    case gain_control_data_present:
      bitDemand += FDKaacEnc_encodeGainControlData(hBitStream);
      break;


    case esc1_hcr:
      if (syntaxFlags & AC_ER_HCR)
      {
        error = AAC_ENC_UNKNOWN;
      }
      break;

    case spectral_data:
      if (hBitStream != NULL)
      {
        INT spectralBits = 0;

          spectralBits = FDKaacEnc_encodeSpectralData( psyOutChannel[ch]->sfbOffsets,
                                                       pChSectionData,
                                                       qcOutChannel[ch]->quantSpec,
                                                       hBitStream );

        if (spectralBits != qcOutChannel[ch]->sectionData.huffmanBits) {
          return AAC_ENC_WRITE_SPEC_ERROR;
        }
        bitDemand += spectralBits;
      }
      break;

      /* Non data cases */
    case adtscrc_start_reg1:
      if (hTpEnc != NULL) {
        crcReg1 = transportEnc_CrcStartReg(hTpEnc, 192);
      }
      break;
    case adtscrc_start_reg2:
      if (hTpEnc != NULL) {
        crcReg2 = transportEnc_CrcStartReg(hTpEnc, 128);
      }
      break;
    case adtscrc_end_reg1:
    case drmcrc_end_reg:
      if (hTpEnc != NULL) {
        transportEnc_CrcEndReg(hTpEnc, crcReg1);
      }
      break;
    case adtscrc_end_reg2:
      if (hTpEnc != NULL) {
        transportEnc_CrcEndReg(hTpEnc, crcReg2);
      }
      break;
    case drmcrc_start_reg:
      if (hTpEnc != NULL) {
        crcReg1 = transportEnc_CrcStartReg(hTpEnc, 0);
      }
      break;
    case next_channel:
      ch = (ch + 1) % numberOfChannels;
      break;
    case link_sequence:
      list = list->next[decision_bit];
      i=-1;
      break;

    default:
      error = AAC_ENC_UNKNOWN;
      break;
    }

    if (error != AAC_ENC_OK) {
      return error;
    }

    i++;

  } while (list->id[i] != end_of_sequence);

bail:
  if (pBitDemand != NULL) {
    *pBitDemand = bitDemand;
  }

  return error;
}


//-----------------------------------------------------------------------------------------------

AAC_ENCODER_ERROR FDKaacEnc_WriteBitstream(HANDLE_TRANSPORTENC hTpEnc,
                                           CHANNEL_MAPPING *channelMapping,
                                           QC_OUT *qcOut,
                                           PSY_OUT* psyOut,
                                           QC_STATE *qcKernel,
                                           AUDIO_OBJECT_TYPE  aot,
                                           UINT  syntaxFlags,
                                           SCHAR  epConfig
                                          )
{
  HANDLE_FDK_BITSTREAM hBs = transportEnc_GetBitstream(hTpEnc);
  AAC_ENCODER_ERROR ErrorStatus = AAC_ENC_OK;
  int   i, n, doByteAlign = 1;
  INT   bitMarkUp;
  INT   frameBits;
  /* Get first bit of raw data block.
     In case of ADTS+PCE, AU would start at PCE.
     This is okay because PCE assures alignment. */
  UINT alignAnchor = FDKgetValidBits(hBs);

  frameBits = bitMarkUp = alignAnchor;


  /* Channel element loop */
  for (i=0; i<channelMapping->nElements; i++) {

    ELEMENT_INFO elInfo = channelMapping->elInfo[i];
    INT elementUsedBits = 0;

    switch (elInfo.elType)
    {
        case ID_SCE:      /* single channel */
        case ID_CPE:      /* channel pair */
        case ID_LFE:      /* low freq effects channel */
        {
          if ( AAC_ENC_OK != (ErrorStatus = FDKaacEnc_ChannelElementWrite( hTpEnc,
                                                      &elInfo,
                                                       qcOut->qcElement[i]->qcOutChannel,
                                                       psyOut->psyOutElement[i],
                                                       psyOut->psyOutElement[i]->psyOutChannel,
                                                       syntaxFlags,   /* syntaxFlags (ER tools ...) */
                                                       aot,           /* aot: AOT_AAC_LC, AOT_SBR, AOT_PS */
                                                       epConfig,      /* epConfig -1, 0, 1 */
                                                       NULL,
                                                       0 )) )
          {
            return ErrorStatus;
          }

          if ( !(syntaxFlags & AC_ER) )
          {
            /* Write associated extension payload */
            for (n = 0; n < qcOut->qcElement[i]->nExtensions; n++) {
              FDKaacEnc_writeExtensionData( hTpEnc,
                                           &qcOut->qcElement[i]->extension[n],
                                            0,
                                            alignAnchor,
                                            syntaxFlags,
                                            aot,
                                            epConfig );
            }
          }
        }
        break;

        /* In FDK, DSE signalling explicit done in elDSE. See channel_map.cpp */
        default:
          return AAC_ENC_INVALID_ELEMENTINFO_TYPE;

    }   /* switch */

    if(elInfo.elType != ID_DSE) {
      elementUsedBits -= bitMarkUp;
      bitMarkUp        = FDKgetValidBits(hBs);
      elementUsedBits += bitMarkUp;
      frameBits       += elementUsedBits;
    }

  } /* for (i=0; i<channelMapping.nElements; i++) */

  if ( (syntaxFlags & AC_ER) && !(syntaxFlags & AC_DRM) )
  {
    UCHAR channelElementExtensionWritten[(8)][(1)]; /* 0: extension not touched, 1: extension already written */

    FDKmemclear(channelElementExtensionWritten, sizeof(channelElementExtensionWritten));

    if ( syntaxFlags & AC_ELD ) {

      for (i=0; i<channelMapping->nElements; i++) {
        for (n = 0; n < qcOut->qcElement[i]->nExtensions; n++) {

          if ( (qcOut->qcElement[i]->extension[n].type==EXT_SBR_DATA)
            || (qcOut->qcElement[i]->extension[n].type==EXT_SBR_DATA_CRC) )
          {
            /* Write sbr extension payload */
            FDKaacEnc_writeExtensionData( hTpEnc,
                                         &qcOut->qcElement[i]->extension[n],
                                          0,
                                          alignAnchor,
                                          syntaxFlags,
                                          aot,
                                          epConfig );

            channelElementExtensionWritten[i][n] = 1;
          } /* SBR */
        } /* n */
      } /* i */
    } /* AC_ELD */

    for (i=0; i<channelMapping->nElements; i++) {
      for (n = 0; n < qcOut->qcElement[i]->nExtensions; n++) {

        if (channelElementExtensionWritten[i][n]==0)
        {
          /* Write all ramaining extension payloads in element */
          FDKaacEnc_writeExtensionData( hTpEnc,
                                       &qcOut->qcElement[i]->extension[n],
                                        0,
                                        alignAnchor,
                                        syntaxFlags,
                                        aot,
                                        epConfig );
        }
      } /* n */
    } /* i */
  } /* if AC_ER */

  /* Extend global extension payload table with fill bits */
  if ( syntaxFlags & AC_DRM )
  {
    /* Exception for Drm */
    for (n = 0; n < qcOut->nExtensions; n++) {
      if ( (qcOut->extension[n].type == EXT_SBR_DATA)
        || (qcOut->extension[n].type == EXT_SBR_DATA_CRC) ) {
        /* SBR data must be the last extension! */
        FDKmemcpy(&qcOut->extension[qcOut->nExtensions], &qcOut->extension[n], sizeof(QC_OUT_EXTENSION));
        break;
      }
    }
    /* Do byte alignment after AAC (+ MPS) payload.
       Assure that MPS has been written as channel assigned extension payload! */
    if (((FDKgetValidBits(hBs)-alignAnchor+(UINT)qcOut->totFillBits)&0x7)!=(UINT)qcOut->alignBits) {
      return AAC_ENC_WRITTEN_BITS_ERROR;
    }
    FDKaacEnc_ByteAlignment(hBs, qcOut->alignBits);
    doByteAlign = 0;

  } /* AC_DRM */

  /* Add fill data / stuffing bits */
  n = qcOut->nExtensions;
  qcOut->extension[n].type = EXT_FILL_DATA;
  qcOut->extension[n].nPayloadBits = qcOut->totFillBits;
  qcOut->nExtensions++;

  /* Write global extension payload and fill data */
  for (n = 0; (n < qcOut->nExtensions) && (n < (2+2)); n++)
  {
    FDKaacEnc_writeExtensionData( hTpEnc,
                                 &qcOut->extension[n],
                                  0,
                                  alignAnchor,
                                  syntaxFlags,
                                  aot,
                                  epConfig );

    /* For EXT_FIL or EXT_FILL_DATA we could do an additional sanity check here */
  }

  if (!(syntaxFlags & (AC_SCALABLE|AC_ER))) {
    FDKwriteBits(hBs, ID_END, EL_ID_BITS);
  }

  if (doByteAlign) {
    /* Assure byte alignment*/
    if (((alignAnchor-FDKgetValidBits(hBs))&0x7)!=(UINT)qcOut->alignBits) {
      return AAC_ENC_WRITTEN_BITS_ERROR;
    }

    FDKaacEnc_ByteAlignment(hBs, qcOut->alignBits);
  }

  frameBits -= bitMarkUp;
  frameBits += FDKgetValidBits(hBs);

  transportEnc_EndAccessUnit(hTpEnc, &frameBits);

  if (frameBits != qcOut->totalBits + qcKernel->globHdrBits){
    return AAC_ENC_WRITTEN_BITS_ERROR;
  }

  return ErrorStatus;
}

